Buddhism is derived from the teachings of Siddhartha Gautama, the Buddha, who lived in northern India from around 560 to 480 BC. The Buddha rejected many features of the Brahmanic tradition of Hinduism and formulated instead a pragmatic system which owes a certain amount to the religious and philosophical questionings of his times. Buddhism eventually became the principle religion of much of Asia and the far east.
Today, Buddhism is represented by many different sects, but within broad Buddhism there are the Theravada, Mahayana and Vajrayana (Tantra). While these differences are beyond the scope of this reference, Theravada (a unified system known as the "Way of the Elders") is considered to be the more conservative branch.
Buddhism focuses on the teaching of the Buddha, scriptures, rites, and the bodhisattva ideal. Buddhism, like all religious disciplines, traces its practices and teachings to an enlightened individual, and for this reason all schools of Buddhism have been careful to preserve records of teaching lineages, which serves as an authentication of their practice. It is a very ancient Buddhist custom to detail the ancestry of a teaching.
The teaching of the Buddha centers on the Four Noble Truths, essentially the foundation of all Buddhism. The Four Noble Truths are:
1. The unsatisfactory nature of all existence, or 'duhkha'.
2. The cause of duhkha.
3. The cessation of duhkha.
4. The path leading to the cessation of duhkha.
Sangharakshita, A Survey of Buddhism (5th edition. Boulder: Shambhala, 1980); Walpola Rahula, What the Buddha Taught (2nd edition. London: Gordon Fraser, 1978); Paul Williams, Mahayana Buddhism (London & New York: RKP, 1989). Crosby and Skilton, The Bodhicaryavatara (1996); Heinz Bechert, and Richard Gombrich, The World of Buddhism (1984); A. L. Herman, An Introduction to Buddhist Thought (1984); Trevor Ling, A Dictionary of Buddhism (1981).